In the scientific study of small wadable streams and rivers, it is desirable to take accurate readings of the various hydrological characteristics of the stream, particularly river flow. In a flowing river which is not too deep to wade, flow determination can be conveniently accomplished by stretching a tagline across the river to determine width, using a wading rod to measure depth, and employing a current meter to measure flow velocity. The total river flow can then be determined by the equation Q=AV, where Q is the total river discharge, A=area of river cross-section, and V=velocity. By measuring stream width with a tagline, and depth with a wading rod, the cross-sectional area of a river can be determined by a wading hydrographer.
At present, hydrographers who wish to use the tagline method do not have a great variety of tagline reels to choose from in carrying out stream width measurements. The most commonly used reel to use with a tagline is the Pakron reel (as disclosed in Buchanan et al., "Discharge Measurements at Gaging Stations, U.S. Geological Survey, 1969, pp. 17-21), which is no longer being manufactured. Unfortunately, the Pakron reel suffers from various shortcomings. First of all, the reel is made entirely of metal, and has a drag assembly which is extremely complex, being composed of many "swiss watch" type small gears and other moving parts. These features make the Pakron reel bulky, expensive, and very susceptible to drag assembly failure with minimal exposure to the elements. Often, a small amount of mud or muddy water is all that is necessary to foul up the drag assembly, and these problems cannot be easily overcome by rinsing the assembly. In addition, the Pakron reel has a small reel capacity (only about 300 feet) and a lock-down or stationing device at one end which cannot be used as a handle. To overcome the shortcomings of this and other prior art tagline reels, it is desirable to obtain a reel which is lightweight, inexpensive and simple to use, which has a maintenance free drag assembly not prone to fouling up under normal conditions, which has a stationing device that can double as a handle for the reel, and which has an enlarged spool capacity.